With increasing numbers of hospitals, clinics, and dental offices moving to fully computerized patient record systems, the number of computer keyboards and mice in these facilities has been steadily increasing. Keyboards and mice contaminated with pathogens have been identified as one of the leading vectors for transmission of infections and viruses from patient to patient in hospitals and clinics. Healthcare acquired infections such as MRSA (Methicillin Resistant Staphylococcus Aureus) cause tens of thousands of deaths each year in the US alone, cost the economy billions through extended hospital stays and wrongful death lawsuits, and contribute to rising medical costs worldwide. A significant percentage of patient to patient transmission of pathogens can be eliminated if there is an effective and simple way to sanitize computer keyboards and mice after each use.
Hand washing policies and regular keyboard cleaning policies have had limited effectiveness in practice since they must take place before every use to eliminate any possibility of patient to patient contamination through the hands of a healthcare worker. Large medical facilities with hundreds or thousands of computer keyboards and mice have deemed it impractical to manually sanitize them with disinfectant more than once or twice per day, even though they may be used by dozens of contaminated employees in between cleanings.
Beyond the hospital setting, there are several other environments in which keyboards or other such equipment are shared by multiple users, thereby facilitating the transfer of germs from one person to another. One such example includes keyboards and mice for computers in typical public libraries.
Germicidal short wave ultraviolet light at 253.7 nm is known as an effective, rapid way to sanitize non-porous, flat surfaces. The germ killing effectiveness of such lamps is a function of total UV energy exposure which is the mathematical product of intensity (power per unit area) and time. Lamps which generate this wavelength are readily available commercially. However, the output of commonly available UV lamps drops significantly over time, and is also affected by voltage, current, manufacturing differences between lamps, and accumulation of dust and other contaminants on the bulb.
Others have tried to construct UV sanitation enclosures, with limited success. U.S. Pat. No. 6,278,122 by Gagnon describes a UV sanitization enclosure for a mouse and keyboard with a sliding drawer mechanism in which a front door hinged at the bottom doubles as a palm rest. U.S. Pat. No. 6,458,331 by Roberts eliminates the drawer mechanism and describes a simple box with a switch which is placed over a mouse and keyboard to be sterilized. U.S. Pat. No. 7,372,044 by Ross describes various configurations of a sanitization box housing various input devices with a window which blocks UV and passes visible light. Each of these devices includes one or more of the shortcomings listed above, or has yet other problems.